Mariah Ross Period 8 Adaption of teeth among sharks Shark teeth often change size and shape based on its position in the shark’s mouth, whether it’s from the upper or lower jaw, and the age, sex, and species of the shark it came from. Shark teeth are produced and shed serially moving forward as though they are on a conveyor belt. With this replacement system, one shark can produce, use, and shed as many as 6,000 teeth each year. If a shark tooth is well preserved it offers the scientist a number of points that can be used to identify the species and the basic taxonomic group of shark it came from. However a great number of shark tooth fossils aren’t well preserved and are often times worn down to the point being smooth and featureless, making them all but useless in the identification process. Early Fossil Shark Teeth and consequent evolution The earliest known fossil shark teeth are those of Leonodus (left) dating back some 400 million years. Their overall crown shape vaguely resembles that of fossilized Xenacanthus (right) teeth, possibly indicating that these early sharks were related. Their roots, however, are quite different, suggesting that Leonodus and Xenacanthus may have evolved similar crowns as an adaptation to feeding on similar prey rather than due to shared ancestry. No one is sure which group of sharks evolved in to their modern counterparts, but until recently many scientists believed that it was the Hybodonts. However, paleoichthyologist John G. Maisey’s extensive studies of fossil and modern sharks, causes some belief that the hybodonts were a side-branch of shark evolution that did not give rise to any group of modern shark. Maisey has proposed that a genus known as Synechodus may be more closely related to ... ... middle of paper ... ...ark can eat 1% to 10% of its overall body weight per week. Many shark species swallow their food whole without any form of chewing. While some sharks are probably not very selective feeders, certain sharks eat some foods more than others. For example, hammerhead sharks are known to eat stingrays; bull sharks eat other sharks; and smooth dogfish eat crabs and lobsters. Tiger sharks feed opportunistically on both live food and carrion. Their prey includes bony fishes, other sharks, marine mammals, seabirds, and invertebrates. How Sharks Work by Tom Harris, http://animals.howstuffworks.com/fish/sharks/shark4.htm Martin, R. Aidan. 2003. Copyright and Usage Policy. World Wide Web Publication, www.elasmo-research.org/copyright.htm http://seaworld.org/en/animal-info/animal-infobooks/sharks-and-rays/diet-and-eating-habits/ NO AUTHOR LISTED, DIET AND EATING HABITS
Mojetta wrote about prehistoric sharks, and the history of these creatures. According to Angelo Mojetta, author of Sharks, Cladoselache genus, one of the first prehistoric sharks, was buried in sediment that kept it preserved. Unlike other sharks, Cladoselache genus had a circle of tiny plates around it’s eyes for protection against it’s victim’s attempts to fight back. These sharks lived over 400 million years ago. Sharks of the past could mostly be identified by their teeth, because shark’s bodies are made of cartilage. Another shark that was focused on was called, Stethacanthus. This shark had a very unique look. Stethacanthus had a brush like decoration on the top of it’s head, and an extra fin like part that had the same bristle like decorations on it. These characteristics were thought to be used as suction cups, to hitch rides from larger fish. One of the most famous sharks that looks like an over...
The relationship of the three species and their ancestors can be summarized by looking at the fossils above. It is evident that all of these three species possess fangs and other types of sharp, prominent teeth. These analogous features indicate that there is some similarity in ancestry, since they all form part of the same family group, although they come from different genus. However, there is some difference in the shape of the head. The coyote possesses a straighter jaw and more angular head. The wolf, on the other side, has a wider denture similar to the fox. These three species also share Homologous structures, such as fangs, are present in these species. Another homologous structure is the legs and ribs, since they all have a similar
In my research, the Oceans of Kansas organization for Paleontology has given me more than enough to focus on when depicting out how to correlate our modern logic about how Kansas is mostly a wasteland to when it used to be an ocean with striving life within. The sharks that have been recently discovered are increasing not only in size, but by type. Mike Everhart, lead Paleontologist of this organization, in April 2002 discovered an extremely large shark called the Cretoxyrhina Mantelli "Ginsu Shark". “A large lamniform shark found worldwide from Turonian into Campanian time during the Late Cretaceous. Much the same size as a modern Great White (but not closely related), the Ginsu shark reached lengths of more than 6 meters before becoming extinct about 82 million years ago.
You are smelling the salty water around you and you suddenly feel something pass your leg.It`s a bull shark waiting to devour you.These species and the hammerhead are the two species of shark that you would not want to be noticed by.Both species are extremely dangerous and deadly.Bull and hammerhead sharks have many similarities and differences.The differences between these two species concerning apperance,diet,size and other important factors of the species` lives are important to know in case of close encounter and need of survival.It is important to know what they look like so it is easier to identify them and to know their special abilities so they will be easier to evade.Hammerhead sharks and bull sharks are very aggressive towards their prey and take over most oceans.These species are very important because if you want to study them for research,then you should know their normal personality traits for easier behavioral comparisons.
The name ‘Liopleurodon’ is derived from Greek. It means “smooth-sided teeth”. The name was given by Henri Emile Sauvage. Sauvage gave this name because in 1873, he found the fossils of three teeth which were just 7 centimeter in length. The two species of Liopleurodon are L. ferox and L. pachydeirus Out of the two species, L. forex is quite known and famous. The fossils of both the species are found in the countries of England and France. L. pachydeirus is a very rare species as its fossils are not discovered in very good numbers. On the other hand, the fossils of L. ferox species are found in comparatively good number. The scientists have more knowledge about L. ferox because of the availability of the skeletons; some of which are more complete or less.
The Great Shark debate – to cull or not to cull, has been at the forefront of the minds of conservationists, as well as the general population for many decades now. The opinions of everyone are divided, according to their personal experiences, and views on what is right and wrong for the environment.
The tooth is to represent how boys’ memories are flawed and unreliable. The first time the shark tooth was found was when they were going through Granddads shed and found remnants of mums’ car. It was found underneath a car seat, and when Harry first showed it, Miles said, without hesitation “White Pointers tooth”. (pg. 92) This shark tooth brought back memories of the night their Mum died, which made them rethink what really happened.
The origin of modern day whales, a mystery that has puzzled paleontologists for years, may have just been solved with the discovery of an ankle bone. This discovery might sound simple and unimportant, but the bones of these ancient animals hold many unanswered questions and provide solid proof of origin and behavior. The relationship between whales and other animals has proven to be difficult because whales are warm-blooded, like humans, yet they live in the sea. The fact that they are warm-blooded suggests that they are related to some type of land animal. However, the questions of exactly which animal, and how whales evolved from land to water, have remained unanswered until now.
Thesis: Sharks should be conserved because they are an important part of the ocean, attacks are often incidental, and human behavior influences the behavior of sharks.
Most people think that sharks are large, fast-swimmers, and savage predators. This is true of some species and groups should be interested of the appealing aspects of biology found within it: all sharks have an excellent sense of smell; some can detect electrical discharges; some sharks give birth to one of the
Sallan, Lauren Cole, and Michael I. Coates. "End-Devonian Extinction and a Bottleneck in the Early Evolution of Modern Jawed Vertebrates." Diss. Cambridge University, 2010. 17 May 2010. Web. 25 Apr. 2012. http://www.pnas.org
There are nearly 400 different types of sharks that have been identified to this day, yet there are still new sharks being recognized every day. Atelomycterus marmoratus, also known as the coral catshark, is a member of the scyliorhinidae family, which is the largest shark family. The coral catshark belongs to the animalia kingdom, chondrichthyes class, elasmobranchii subclass, and the A. marmoratus species. Another common name for the coral catshark is the marbled catshark, which came from the original name, Scyllium Marmoratum. (Marmoratum being Latin for marbled) The life of the coral catshark is exposed and defined by looking in to the physical description, habitat and adaptations, feeding behavior, life history, and conservation status and threats.
Sharks: Man-eating, stealthy, carnivorous creatures that roam the ocean. What could possibly come in the way of such beasts? Certainly puny humans could not interfere with these brutes. Or could we? It is estimated that over one hundred million sharks are killed each year (Why Are Sharks Endangered). All one hundred million deaths are due to mankind.
Forensic dentists have played a major role in the identification of remains in mass disasters, in crime investigations, in ethnic studies, and in the identification of decomposed and disfigured bodies in situations such as fire and car accidents (1). Teeth are considered to be a great form for identification as teeth are mostly composed of enamel. Enamel is the hardest tissue in the body and can withstand extremely harsh conditions (1). Two forms of dental identification of humans exist. These two forms are comparative and when no ante-mortem (before death) dental records are available. The comparative form of identification compares the ante-mortem and post-mortem (after death) dental records (1). Dental records con...
One particularly interesting sea creature is the whale shark, formally known as Rhincondon typus it was first discovered in 1828 by Andrew Smith (Rowat 2012). This large fish is found globally in warm tropical oceans and prefers to stay within 200 meters of the ocean’s surface in waters ranging from 4.2 to 28.7 degrees Celsius (Stevens 2006). This creature can be found all across the globe in any warm tropical seas. Aggregations of whale sharks have been seen off the coast of Australia at times, although it is primarily a creature of solitude. Whale sharks are filter feeders that consume plankton as well as small fish and are harmless to humans. The whale shark is a species with a fascinating ecology, life history, behavior, anatomy